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inning the secreted fluids and causing anevolution of caloric from the blood, after thenervous influence is withdrawn," &c.The brain may be considered as the

receptaculum commune of the electric or

nervous fluid, which it receives through themedium, principally, of the spinal marrow,from the various nerves of the body, thenerves being, certainly, the best conductorsof electricity among the animal textures.Probably there is not at any time (in ordi-nary cases) a great accumulation of thelatter agent in the system ; for the demandson the fund are manifold, particularly forcarrying on the functions of respiration,digestion, and secretion, which are so con.stantly in action that the expenditure at mosttimes equals the supply. Its being other-wise may probably be the cause of madnessin some cases in which, after death, no Ilesion of structure is perceptible in thebrain, which may have been over-excited.An undue electrical excitement of the mental

organ may, by a parity of reasoning, beproductive of idiotism in various of its

forms, and of the stupidity which attendsa continual indulgence in the pleasures ofthe table.

Considering the convolutions of the cere-bral hemispheres as the organ of the intel-lect, to the medulla oblongata (meaningthereby all the inferior part of the cerebrumfrom which the nerves of sense arise) mustbe attributed the office of receiving the im-pressions of the senses, which it communi-cates to the mind by the blending of itsnervous fibres with those of the hemispheresin the medullary portion of the latter. Thefact that the medulla oblongata is formed bythe crura cerebri et cerebelli, or, at least,that these enter very largely into its compo-sition, sufficiently accounts for the close

blending of the animal functions, with themental.The state of being awake or alive to all

the impressions of sense, appears to be thatin which the current of electricity passesthrough or is extended to the medulla

oblongata, and thus are the senses and allthe functions in a state of excitement ;whereas, in sleep, the stream of electricitytakes a different course, or perhaps whollypasses off by the pneumogastric and respi-ratory nerves, which, it will be remembered,arise from the inferior part of the medulla,or perhaps we might more properly say,the summit of the spinal marrow. Henceit is that digestion and the secretive pro-cesses are much more active during thestate of sleep; and that dreams, we mayinfer, are occasioned by the excitement ofthe intellectual organ, the before-mentionednerves not withdrawing a quantity of elec-tricity equal to the supply; thus is it alsodifficult to sleep with an empty stomach,and thus the reverse of this, how great thepropensity to sleep after a full meal ! 1

Finally, the spinal marrow and the cere-bellum appended to and surmounting it, areorgans appropriated to volition, and thenumerous functions more particularlycharacterising animal existence ; to theexcitement of which, accompanied withthat of the cerebral organ, during sleep, orunaccompanied with the excitement of themedulla oblongata, may somnambulism beattributed.[We shall insert some subsequent com-

munications of Dr. Searle, to which theabove is an introduction, on an early occa-sion.]

ADVANTAGES OF TAPPING THEBRAIN IN HYDROCEPHALUS.

. MR. BUTCHER, in a late number of theDublin Medical Journal," advocatesstrongly the employment of the trocar to

penetrate the lateral ventricles of the brainin certain cases of hydrocephalus ; and theoperation may, he . considers, be performedwith a successful result at a much laterperiod than it has usually been resorted to.No doubt the serous fluid effused into theventricles becomes at an after period ab-sorbed, and the patient dies from the struc-ture of the brain becoming secondarily in-

volved ; but Mr. Butcher says,-" That ramollissement does not come on

till a later period than is generally supposed,I have verified by dissection. In eight casesthat I have examined of acute hydrocepha-lus, where the head was unusually large, andwhere the children were carried off by infec-tious diseases, not in any of those cases wasthere softening or ramollissement of thestructure of the brain, though the lateralventricles were enormously distended withfluid."

l A case is reported illustrative of the goodeffects obtained by tapping. It was that ofan infant, sixteen months of age, the head ofwhich was almost transparent, and pre-sented in different situations patches wherethe ossific matter was not deposited, its placebeing supplied by the common integuments.The sutures were very considerably sepa-rated, being from half to three-quarters of aninch asunder. The head measured in thefronto-occipital circumference thirteen inchesand a half ; from ear to ear across the vertex,nine inches; round the chin and across thevertex, nine inches and three-quarters."The operation was conducted as follows :" The integuments having been divided

with a lancet, a trocar was introduced aboutthree-quarters of an inch external to the

mesial line, near the junction of the edge ofthe fontanelle with the margin of the parie-

. tal bone. The instrument being inclined alittle inwards, in this manner it was directed, into the lateral ventricle of the right side ; nosooner was the stilet withdrawn than the! fluid flowed out freely through the canula.

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The quantity drawn off amounted to elevenounces. After the discharge of so large aquantity of fluid, the head lost its tensionand globular form, and became so flaccid asto allow the remaining quantity of water togravitate backwards, giving the head a veryelongated appearance. To support the partsa double-headed roller was applied loosely,the edge of the incision being previouslybrought together with adhesive plaster. Thechild sunk very low immediately after theoperation; however, after some time, theurgent symptoms were suppressed. Fromthis period up to four weeks after, every-thing was doing remarkably well; the head If,filled again, but not to one-half of its origi- Inal size. The operation was again per- iformed on the left side, in the same situationas on the right. The child began visibly to

’’

improve ; no convulsions whatever occurredafter the first operation; four weeks moreelapsed, and the head was not near the sizeit presented before the second operation ; somuch was it lessened that another operationwas deferred for a future period."Though the result was so eminently suc-

cessful, it is lamentable to think that thepatient should afterwards have succumbedthrough ill-treatment.

11 Ten weeks had elapsed ; the childwas free from convulsions; the eyes werequite sensible to light, and the little patientdid not exhibit any lethargic symptoms. Infour days after he began to get uneasy andrestless; three more had not passed by whenhe was seized with convulsions that termi-nated in death. I was immediately calledto see the child, and having accused themother of neglecting it in some way she ac-knowledged to have given it wine regularlyfor five days before, stating, as her reasonfor doing so, She thought it would hastenthe cure, and not do him any harm ; he wasso much better."’

SECRETIONS DERIVED FROMVENOUS BLOOD ALONE:

A TRUE

PORTAL SYSTEM IN THE KIDNEY.

In an able paper in the " Dublin Journalof Medical Science," Dr. Aldridge bringsforward the view that a true portal systemexists in the kidney, and that the peculiarsecretion elaborated by that gland is like thesecretion of the liver derived from venousblood, as asserted by Mr. Bowman in the" Philosophical Transactions" of the pastyear. This view is so novel, and, at thesame time, so well entitled to demand ex-tended publicity, that its merits may be suf-ficiently canvassed, that we do not deem itnecessary to make any apology for intro.

ducing copious extracts, comprising themain points of the argument in the following

columns. Dr. Aldridge states that in 1889he remarked on " the improbability of theopinion generally entertained that urine issecreted from arterial blood. I asked whyshould the kidney differ from the other greatemunctories in this particular? The liverand lungs secrete from venous blood; and isit not reasonable to think that in every in.stance the means of depuration should be im.plied to the impure fluid ? ....... Jacobsonhas discovered that in fishes and reptiles theurine is secreted by venous blood. Is itlikely so great a difference could exist be-tween the performance of this function in

contiguous groups of all vertebrated ani.mals ? ?" Mr. Bowman, in a paper published ill

the Philosophical Transactions’ during thepast year, has ascertained that the kidney isfurnished with a true portal system and thaturine (like the bile) is secreted, in part, atleast, from blood traversing, at the time, asecond set of capillaries."According to him the exceedingly tor.

tuous and convoluted urinary conduits ter.minate at their final extremities, each by acontracted neck, which conducts into a littlechamber or cyst. In this cyst is containedthe true glandule of Malpighi, which consistsof a tuft or coil of capillary blood-vessels,totally naked, which originates in one of theultimate branches of the renal artery, andterminates in an efferent vessel. Several ofthese latter form, by their anastomosingrami.fications, the plexus that surrounds each uri-nary conduit and tubule ; the urinary con.

duits are lined by thick epithelium, andtheir necks are furnished by vibratilecilia.

" All the blood of the renal artery," saysMr. Bowman "(with the exception of a

small quantity distributed to the capsule,surrounding fat, and the coats of the largervessels), enters the capillary tufts of the

Malpighian bodies; thence it passes into thecapillary plexus surrounding the uriniferoustubes, and it finally leaves the organ throughthe branches of the renal vein.

" thus, there are in the kidney two per’fectly distinct systems of capillary 1Jessels; the1st, that inserted into the dilated extremitiesof the uriniferous tubes, and in immediateconnection with the arteries (the Malpighianbodies); the 2nd, that enveloping the con.volutions of the tubes, and communicatingdirectly with the veins. The efferent ves.sels of the Malpighian bodies that carry theblood between these two systems, may col,lectively be termed the portal system of thekidney."The former, which may be styled the

Malpighian capillary system, is made up ofas many parts as there are Malpighianbodies. These parts are entirely isolatedfrom one another ; and, as there is no inosculation between the arterial branches supplying them, the blood enters each in a direct